The present invention relates to an apparatus for controlling periodic flashings of vehicle directional lamps and particularly to an improvement in the protection of the semiconductor integrated circuit which control the periodic flashings of the directional lamps.
It is known well in the turn-direction indicating system of an automotive vehicle that a group of front,rear and side directional lamps are energized in response to periodic pulses produced by an electronic control circuit designed to be integrated into a semiconductor chip. One of this system is disclosed in the U.S. Pat. No. 3,858,177 issued on Dec. 31, 1974, for example.
Such a semiconductor integrated control circuit is connected to a storage battery. Other electric devices such as electric motors, relays and ignition coils which often generate undesired excessively large voltage are also connected to the storage battery. When the undesired voltage exceeds .+-.100 volts, the semiconductor integrated circuit which has a maximum allowable voltage of 40.about.60 volts when manufactured in a bipolar linear integrated circuit process is broken down.